1. Field of the Invention
The present invention generally relates to a film deposition apparatus, a film deposition method, and a computer-readable recording medium for forming plural layers of a reaction product on a surface of a substrate and performing plasma modification by sequentially supplying process gases that react to each other.
2. Description of the Related Art
As one method for depositing a thin film (e.g., silicon oxide film (SiO2)) on a substrate such as a semiconductor wafer, there is an Atomic Layer Deposition (ALD) method. The ALD method forms plural layers of a reaction product by sequentially supplying plural types of process gases (reaction gases) to a surface of a wafer. For example, Japanese Laid-Open Patent Publication No. 2010-239102 discloses a known film deposition apparatus that performs a film deposition process using the ALD method. The known apparatus has plural wafers arranged on a rotation table inside a vacuum chamber in a circumferential direction of the rotation table and has the rotation table rotated relative to plural gas supplying parts arranged in a manner facing, for example, the rotation table. Thereby, the process gases can be sequentially supplied to the plural wafers.
The wafer heating temperature (film deposition temperature) of the ALD method is, for example, 300° C. The wafer heating temperature of the ALD method is low compared to that of an ordinary Chemical Vapor Deposition (CVD) method. This may cause organic materials contained in the process gases to enter the thin films as impurities. As described in Japanese Laid-Open Patent Publication No. 2011-40574, by performing modification using plasma together with thin film deposition, such impurities can be reduced or removed from the thin films.
However, in a case of performing modification with a plasma process apparatus that is separate from the above-described film deposition apparatus, there is a loss of time due to conveying of wafers between the plasma process apparatus and the film deposition apparatus. This may lead to decrease of throughput. Meanwhile, in a case of a film deposition apparatus combined with a plasma source for generating plasma, a modification process may be performed concurrently with or after performing a film deposition process. In this case, the plasma may electrically damage a wiring structure formed inside the wafer. In order to reduce the damage caused by the plasma, the plasma source may be separated away from the wafer. However, by separating the plasma source away from the wafer, the active species (e.g., ions, radicals) inside the plasma may be deactivated due to pressure conditions for performing a film deposition process. Thus, it is difficult to perform a satisfactory modification process due to the active species being unable to reach the wafer.
Although U.S. Pat. No. 7,153,542, Japanese Registered Patent No. 3144664, and U.S. Pat. No. 6,869,641 describe film deposition apparatuses using the ALD method, resolving such difficulties is not taught in U.S. Pat. No. 7,153,542, Japanese Registered Patent No. 3144664, and U.S. Pat. No. 6,869,641.